The transport of multi-phase fluids, e.g. of a gas and liquid, is often necessary in oil and gas pipelines. In such cases, the density and other properties of e.g., the gas and liquid are different and lead to differences in the velocity of the flow of each phase being transported. For example, because the gas phase velocity may be higher that the velocity of the liquid phase, the transport of one or more of the phases using pipe may be less efficient as compared to a single-phase flow e.g., a heavier liquid phase may significantly block the flow of lighter phase. An increase in pressure due to such flow resistance can cause pressure build-up and damage to the pipe. Additionally, uneven flow stemming from the transport of multiphase fluids can cause problems at the end or terminus of the pipe. The transport of oil and/or natural gas may typically involve a simultaneous flow of a gaseous phase and a liquid phase of the fluid being transported.
Steel pipe is commonly used in the oil and gas industry. However, steel pipelines, gathering lines or injection lines are usually installed using short (30-40 foot) sections. This requires additional labor and provides the possibility for fluid leakage at each fitting. Such labor intensive installation may also lead to lost revenues if production or transport of the fluids is suspended during the installation.
Further, such steel pipe is subject to corrosion. To resist internal corrosion, steel alloys, non-metallic internal coatings, or fiberglass-reinforced epoxy pipe may be used, but all may still have the disadvantage of being sectional products. In some applications, thermoplastic liners may be used as corrosion protection inside steel pipe, but these liners are susceptible to collapse by permeating gases trapped in the annulus between the liner and the steel pipe if the pressure of the bore is rapidly decreased.
There is a need for substantially non-corrosive pipe that is capable of transporting multi-phase fluids, such as may be used in the oil and gas industry.